Communication control method, communication system, and transmission apparatus

ABSTRACT

An object of the present disclosure is to provide a communication control method capable of preventing excessive bandwidth allocation to a specific apparatus. A communication control method according to the present disclosure includes: estimating a quality of experience of a monitoring person who monitors videos displayed on a monitoring apparatus (30) that has received video data of the videos captured by a plurality of imaging apparatuses (20) via a network (40), when viewing the videos; and controlling communication for transmitting the video captured by each of the imaging apparatuses (20) to the monitoring apparatus via the network based on the estimated quality of experience.

TECHNICAL FIELD

The present disclosure relates to a communication control method, acommunication system, and a transmission apparatus.

BACKGROUND ART

In recent years, self-driving technology has been developed andself-driving vehicles have been tested on public roads. Usually, aself-driving vehicle has various sensors mounted thereon for recognizingthe peripheral state of the vehicle such as the presence or the absenceof a pedestrian and the presence or the absence of another vehicle.Examples of the various sensors include cameras, radars, and lightdetection and ranging (LiDAR). Information detected by the varioussensors is used in performing driving control and remote monitoring.

Patent Literature 1 describes that a communication apparatus determinesa priority level of each camera mounted on a vehicle, and allocates, toeach camera, a bandwidth for transmitting a video to a server device, inaccordance with the priority level.

CITATION LIST Patent Literature

Patent Literature 1: International Patent Publication No. WO2020/090285

SUMMARY OF INVENTION Technical Problem

However, in a case where a bandwidth is allocated in accordance with apriority level of each of a plurality of cameras as in the communicationapparatus disclosed in Patent Literature 1, there is a problem thatthere is a high possibility that an excessive bandwidth is allocated toa camera with a high priority level.

An object of the present disclosure is to provide a communicationcontrol method, a communication system, and a transmission apparatuscapable of preventing excessive bandwidth allocation to a specificapparatus.

Solution to Problem

A communication control method according to a first aspect of thepresent disclosure includes: estimating a quality of experience of amonitoring person who monitors videos displayed on a monitoringapparatus that has received video data of the videos captured by aplurality of imaging apparatuses via a network, when viewing the videos;and controlling communication for transmitting the video captured byeach of the imaging apparatuses to the monitoring apparatus via thenetwork based on the estimated quality of experience.

A communication system according to a second aspect of the presentdisclosure includes: a transmission apparatus configured to transmit,via a network, video data of videos captured by a plurality of imagingapparatuses; and a monitoring apparatus configured to display the videosreceived via the network, in which the transmission apparatus estimatesa quality of experience of a monitoring person who monitors the videoswhen viewing the videos, and controls communication for transmitting thevideo captured by each of the imaging apparatuses to the monitoringapparatus via the network based on the estimated quality of experience.

A transmission apparatus according to a third aspect of the presentdisclosure includes: an estimation unit configured to estimate a qualityof experience of a monitoring person who monitors videos displayed on amonitoring apparatus that has received video data of the videos capturedby a plurality of imaging apparatuses via a network, when viewing thevideos; and a control unit configured to control communication fortransmitting the video captured by each of the imaging apparatuses tothe monitoring apparatus via the network based on the estimated qualityof experience.

Advantageous Effects of Invention

According to the present disclosure, it is possible to provide acommunication control method, a communication system, and a transmissionapparatus capable of preventing excessive bandwidth allocation to aspecific apparatus.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a configuration diagram of a communication system according toa first example embodiment.

FIG. 2 is a diagram showing a flow of communication control processingaccording to the first example embodiment.

FIG. 3 is a configuration diagram of a transmission apparatus accordingto a second example embodiment.

FIG. 4 is a diagram showing a control image of a vehicle according tothe second example embodiment.

FIG. 5 is a diagram showing transition of a quality of experienceaccording to the second example embodiment.

FIG. 6 is a diagram of a monitoring apparatus according to the secondexample embodiment.

FIG. 7 is a diagram showing a flow of communication control processingaccording to the second example embodiment.

FIG. 8 is a diagram showing a flow of bandwidth allocation processingaccording to the second example embodiment.

FIG. 9 is a diagram showing a flow of bandwidth allocation processingaccording to a third example embodiment.

FIG. 10 is a configuration diagram of a transmission apparatus and amonitoring apparatus according to each example embodiment.

EXAMPLE EMBODIMENT First Example Embodiment

Example embodiments of the present disclosure are described below withreference to the drawings. A configuration example of a communicationsystem according to a first example embodiment will be described withreference to FIG. 1 . The communication system of FIG. 1 includes atransmission apparatus 10, imaging apparatuses 20, and a monitoringapparatus 30. The transmission apparatus 10 communicates with themonitoring apparatus 30 via a network 40.

The transmission apparatus 10, the imaging apparatus 20, and themonitoring apparatus 30 may be computer apparatuses that operate when aprocessor executes a program stored in a memory. The network 40 may be,for example, an IP network. Alternatively, the network 40 may be acommunication network managed by a telecommunications carrier. Thecommunication network managed by the telecommunications carrier may bereferred to as a mobile network. The transmission apparatus 10 may beconnected to the network 40 via a radio communication line. Connectionof the transmission apparatus 10 to the network 40 indicates a state inwhich the transmission apparatus 10 can communicate with the network 40.

Next, a configuration example of the transmission apparatus 10 will bedescribed. The transmission apparatus 10 includes an estimation unit 11and a communication control unit 12. The constituent component of thetransmission apparatus 10 such as the estimation unit 11 or thecommunication control unit 12 may be a software component or a modulewhose processing is carried out by causing the processor to execute theprogram stored in the memory.

Alternatively, the constituent component of the transmission apparatus10 may be a hardware component such as a circuit or a chip.

The estimation unit 11 estimates a quality of experience of a monitoringperson who monitors videos displayed on the monitoring apparatus 30 thathas received video data of the videos captured by the plurality ofimaging apparatuses via the network 40, when viewing the video.

The imaging apparatus 20 may be, for example, a camera apparatus.Although the transmission apparatus 10 and the imaging apparatus 20 areshown as different apparatuses in FIG. 1 , the imaging apparatus 20 maybe mounted on the transmission apparatus 10. That is, the transmissionapparatus 10 and the imaging apparatus 20 may be an integratedapparatus. Furthermore, although FIG. 1 shows a configuration in which aplurality of imaging apparatuses 20 are connected to the transmissionapparatus 10 via one communication line, a communication line may be setfor each imaging apparatus 20.

The video may be, for example, a moving image or a still image. Themonitoring apparatus 30 reproduces the video by using the received videodata. The video data may be referred to as a video file, a video frame,or the like.

For example, in a case where the video data is received from each of theplurality of imaging apparatuses 20, the monitoring apparatus 30 maydisplay the video captured by each imaging apparatus 20 on a displayunit such as a display. That is, the monitoring apparatus 30 may dividea display region of the display and simultaneously display the videoscaptured by the respective imaging apparatuses 20. Alternatively, themonitoring apparatus 30 may combine the pieces of video data from theplurality of imaging apparatuses 20 and display the combined video dataas one video. At this time, display sizes of all the pieces of videodata may be the same, or the display size may be different for eachpiece of video data. In addition, the monitoring apparatus 30 may deletea partial region from the video and display the video without thepartial region on the display unit.

The quality of experience is one of indices indicating a quality of thevideo displayed by the monitoring apparatus 30, and is an indexindicating subjective evaluation by the monitoring person.

The communication control unit 12 controls communication fortransmitting the video captured by each imaging apparatus 20 to themonitoring apparatus 30 via the network 40 based on the estimatedquality of experience.

Controlling communication may mean, for example, determining an encodingparameter of the video data to be transmitted to the monitoringapparatus 30. Examples of the encoding parameter may include a bandwidthto be allocated to transmission of the video data. For example, thecommunication control unit 12 may determine the encoding parameter insuch a way as to improve the quality of experience of the monitoringperson.

The communication control unit 12 may control communication based on thequality of experience regarding the video captured by each imagingapparatus 20, the quality of experience being estimated by theestimation unit 11. Alternatively, the communication control unit 12 maycontrol communication based on the quality of experience estimated bythe estimation unit 11 in comprehensive consideration of the videoscaptured by the respective imaging apparatuses 20.

Estimating the quality of experience in comprehensive consideration ofthe videos captured by the respective imaging apparatuses 20 may beestimating the quality of experience of the monitoring person whosimultaneously views the videos captured by the plurality of imagingapparatuses 20. Generally, when the monitoring person simultaneouslyviews a plurality of videos, in a case where only a quality of a videocaptured by one imaging apparatus 20 is high and qualities of videoscaptured by other imaging apparatuses 20 are low, the quality ofexperience of the monitoring person may not be high. In such a case, itis necessary to improve the overall quality of the videos captured bythe plurality of imaging apparatuses 20 in order to improve the qualityof experience of the monitoring person.

For example, the quality of experience of the monitoring person whosimultaneously views the videos captured by the plurality of imagingapparatuses may be the sum of the qualities of experience of themonitoring person who views the respective videos. In this case, thequality of experience for each video may be weighted when adding up thequalities of experience for the respective videos. A weighted value maybe determined according to priority information of each video, forexample.

Next, a flow of communication control processing in the transmissionapparatus 10 according to the first example embodiment will be describedwith reference to FIG. 2 . First, the estimation unit 11 estimates thequality of experience of the monitoring person who monitors the videosdisplayed on the monitoring apparatus 30 that has received the videodata of the videos captured by the plurality of imaging apparatuses 20via the network 40, when viewing the videos (S11).

Next, the communication control unit 12 controls communication fortransmitting the video captured by each imaging apparatus 20 to themonitoring apparatus 30 via the network 40 based on the estimatedquality of experience (S12).

As described above, the transmission apparatus 10 according to the firstexample embodiment controls communication for transmitting the videodata based on the quality of experience of the monitoring person whomonitors the videos displayed on the monitoring apparatus 30 connectedvia the network 40 when viewing the videos. In addition, the quality ofexperience of the monitoring person is quality for the images capturedby the plurality of imaging apparatuses 20. Therefore, the communicationcontrol unit 12 does not determine the encoding parameter in such a waythat only video data of a specific imaging apparatus 20 has a highquality, but determines the encoding parameter in such a way as toimprove the qualities of all pieces of video data captured by theimaging apparatuses 20. As a result, the communication control unit 12can avoid excessive bandwidth allocation for transmitting the video dataof the specific imaging apparatus 20, and can perform bandwidthallocation in such a way as to improve the qualities of all pieces ofvideo data.

Second Example Embodiment

Next, a configuration example of a transmission apparatus 50 accordingto a second example embodiment will be described with reference to FIG.3 . The transmission apparatus 50 corresponds to the transmissionapparatus 10 of FIG. 1 . The transmission apparatus 50 includes acommunication unit 51, a communication quality acquisition unit 52, areproduction environment acquisition unit 53, an encoding control unit54, a priority level determination unit 55, a quality-of-experiencecalculation unit 56, encoding units 57 to 60, and cameras 61 to 64.

The transmission apparatus 50 may be mounted on a mobile body. Examplesof the mobile body may include a vehicle. Examples of the vehicle mayinclude a self-driving vehicle that is autonomously driven without beingoperated by a driver, or may be a vehicle for which remote monitoring ordriving assistance is performed. For example, as shown in FIG. 4 , thevehicle may be automatically driven or remotely monitored via theInternet. Further, as shown in FIG. 4 , the quality of experience of themonitoring person who monitors the video captured by the imagingapparatus (camera) mounted on the vehicle as the video displayed on themonitoring apparatus received via the Internet is estimated. FIG. 4shows a case where the quality of experience is estimated in anapparatus different from the vehicle. However, as described below, thequality of experience may be estimated in the transmission apparatus 50mounted on the vehicle. The cameras 61 to 64 may capture images of thesurroundings of the vehicle. Specifically, the cameras 61 to 64 may beattached at positions where it is possible to perform imaging in front,rear, left, and right directions of the vehicle. FIG. 3 shows aconfiguration in which the cameras 61 to 64 are used integrally with thetransmission apparatus 50.

The encoding control unit 54 corresponds to the communication controlunit 12 of FIG. 1 . The quality-of-experience calculation unit 56corresponds to the estimation unit 11 of FIG. 1 . In FIG. 3 , functionsor operations different from those of the transmission apparatus 10 ofFIG. 1 will be mainly described, and a detailed description regardingfunctions or operations similar to those of the transmission apparatus10 of FIG. 1 will be omitted.

The communication unit 51 communicates with the monitoring apparatus viathe network 40. Furthermore, the communication unit 51 communicates withthe network 40 via a radio communication line. That is, thecommunication unit 51 transmits a radio frame to the network 40 andreceives a radio frame from the network 40. For example, thecommunication unit 51 may perform wireless communication by using awireless communication standard such as long term evolution (LTE) or 5thgeneration (5G) defined in the 3rd generation partnership project(3GPP).

The communication quality acquisition unit 52 acquires informationregarding a quality of a communication path between the transmissionapparatus 50 and the monitoring apparatus 30 from the monitoringapparatus 30 via the communication unit 51. For example, informationregarding a transmission time from when the transmission apparatus 50transmits the video data to when the monitoring apparatus 30 receivesthe video data may be acquired.

The communication quality acquisition unit 52 calculates a bit rate atwhich transfer can be performed by the transmission apparatus 50 byusing a data size of the video data transmitted to the monitoringapparatus 30 and the transmission time related to the video data. Thebit rate indicates the amount of data that can be transferred per unittime. The bit rate may be referred to as a channel capacity, abandwidth, or simply a band. Furthermore, the bit rate calculated by thecommunication quality acquisition unit 52 may be referred to as anavailable bandwidth. The communication quality acquisition unit 52outputs information regarding the calculated bit rate to the encodingcontrol unit 54. The calculation of the bit rate may be performed in themonitoring apparatus 30, and in this case, the communication qualityacquisition unit 52 of the transmission apparatus 50 may acquire theresult via the communication unit 51.

The reproduction environment acquisition unit 53 acquires informationregarding a reproduction environment in the monitoring apparatus 30 fromthe monitoring apparatus 30 via the communication unit 51. For example,the information regarding the reproduction environment may beinformation regarding screen display in the monitoring apparatus 30, aline of sight of the monitoring person, a reproduction delay, and thelike. Examples of the information regarding the screen display mayinclude information regarding the presence or absence of display ofcamera videos captured by the cameras 61 to 64, a display size of thecamera video on the screen, a difference in display size of each cameravideo, a distance from the screen to the monitoring person, and thelike. Examples of the information regarding the line of sight of themonitoring person may include information regarding whether or not themonitoring person is gazing at the screen. Whether or not the monitoringperson is gazing at the screen may be detected by, for example, a sensorthat tracks the line of sight.

The reproduction environment acquisition unit 53 outputs the informationregarding the reproduction environment to the encoding control unit 54.

The priority level determination unit 55 determines priority informationof a plurality of cameras. For example, the priority level determinationunit 55 determines priority levels of the cameras 61 to 64. The prioritylevel of each camera may be determined based on a traveling direction ofthe vehicle. The traveling direction of the vehicle may be determinedbased on, for example, shift lever information of the vehicle. Further,it is possible to determine whether the vehicle turns right or left byusing steering wheel information or blinker information of the vehicle.Alternatively, the priority level determination unit 55 may acquireinformation regarding the traveling direction of the vehicle fromsoftware that assists driving such as a car navigation system.

For example, a priority level of a camera that captures the travelingdirection of the vehicle may be set higher than those of other cameras.Specifically, when the vehicle is moving forward, a priority level of acamera that images an area in front of the vehicle may be set higherthan those of other cameras. Furthermore, in a case where the vehicleturns right, a priority level of a camera that images an area on theright side of the vehicle may be set higher than those of the othercameras.

Furthermore, the priority level of each camera may be determinedaccording to an object appearing in the video captured by each camera.For example, in a case where another vehicle, a pedestrian, an obstacle,a traffic signal, or a traffic sign appears in a captured video, apriority level of a camera that has captured the video may be set higherthan those of the other camera. Alternatively, the priority leveldetermination unit 55 may determine the priority level according to thetype of lens used for the camera. For example, in a case where thevehicle is stopped or departs, the priority level determination unit 55may increase a priority level of a camera that uses a fisheye lens thatenables checking of a wide range.

For example, the priority level determination unit 55 may set a prioritylevel of a camera with the highest priority among the cameras 61 to 64to 4, may set a priority level of a camera with the second highestpriority to 3, and may set a priority level of a camera with the thirdhighest priority to 2. The priority level determination unit 55 may seta priority of a camera with the lowest priority to 1. The priority levelvalues 1 to 4 determined by the priority level determination unit 55 areexamples, and the priority level may be set to other numerical values.Further, the priority level determination unit 55 may calculate a newpriority level P as P=m(p) by using a determined priority level value pand an arbitrary monotone increasing function m(x). That is, thepriority level determination unit 55 may convert the priority level p tothe new priority level P by using the arbitrary monotone increasingfunction m(x). As a result, for example, it is possible to increase ordecrease a difference between numerical values set for the prioritylevel of the camera with the highest priority and the priority levels ofother cameras. The priority level determination unit 55 outputs thedetermined priority p or P to the encoding control unit 54.

The encoding control unit 54 outputs the information acquired from thecommunication quality acquisition unit 52 and the reproductionenvironment acquisition unit 53 to the quality-of-experience calculationunit 56. Furthermore, the encoding control unit 54 may output, to thequality-of-experience calculation unit 56, a bit rate allocated to thecameras 61 to 64, a frame rate, a resolution, and a codec type. Theresolution may be a resolution of the video data applied when thetransmission apparatus 50 transmits the video data to the monitoringapparatus 30. For example, in a case where a bit rate allocated to acamera is lowered, the encoding control unit 54 may lower at least oneof a frame rate or a resolution when transmitting video data of a videocaptured by the camera to the monitoring apparatus 30 in order toimprove the quality of experience. Furthermore, the encoding controlunit 54 may output installation locations of the cameras 61 to 64,orientations of the cameras 61 to 64, camera types, a vehicle speed,operation information of the vehicle, and the like to thequality-of-experience calculation unit 56.

The quality-of-experience calculation unit 56 calculates a quality q ofexperience by using the information acquired from the encoding controlunit 54 as a parameter. For example, the quality q of experience may bedefined as q=f(x₁, x₂, . . . , x_(N)) using a certain function f(x₁, x₂,. . . , x_(N)) (N is an integer of 1 or more). In this case, the qualityq of experience may be calculated by setting the information acquiredfrom the encoding control unit 54 as a parameter of f(x₁, x₂, . . . ,x_(N)).

For example, an equation defined in ITU-T G. 1070 may be used forq=f(x₁, x₂, . . . , x_(N)) for calculating the quality q of experience.Since the equation defined in ITU-T G. 1070 is a known equation, adetailed description thereof will be omitted.

Alternatively, the monitoring person may perform in advance a subjectiveevaluation experiment of evaluating the quality of the video by viewingthe video in which the parameter acquired by the quality-of-experiencecalculation unit 56 is changed, and model a relationship between theparameter and the quality q of experience by using the experimentresult. Machine learning such as deep learning may be used for thismodeling. Once the information is acquired from the encoding controlunit 54, the quality-of-experience calculation unit 56 may determine thequality q of experience by using a model generated in advance.

The quality-of-experience calculation unit 56 outputs the calculatedquality q of experience to the encoding control unit 54.

The encoding control unit 54 determines the encoding parameter by usingthe quality q of experience acquired from the quality-of-experiencecalculation unit 56 and the priority level p acquired from the prioritylevel determination unit 55.

For example, the encoding control unit 54 defines an objective functionA1 as in the following Equation (1). p_(i) indicates a priority level ofa camera i, and q_(i) indicates a quality of experience for the camerai. The quality of experience for the camera i is a quality of experienceevaluated by the monitoring person who views a video captured by thecamera i. n indicates the number of cameras (n is an integer of 1 ormore).

[Equation 1]

A1=max Σ_(i=1) ^(n) p _(i) q _(i)  (1)

Further, the encoding control unit 54 defines a constraint condition Bas in the following Equation (2). r_(i) indicates a bit rate of thecamera i, and C indicates an available bandwidth.

[Equation 2]

B=Σ _(i=1) ^(n) r _(i) ≤C  (2)

The encoding control unit 54 may determine the encoding parameter insuch a way that A1 is maximized under the constraint condition B.

For example, it may be assumed that the bit rate (bandwidth) allocatedto each camera and the quality of experience of the monitoring personwho views each camera change as shown in FIG. 5 . The horizontal axis inFIG. 5 indicates the bit rate allocated to each camera in bits persecond (bps). The vertical axis indicates the quality of experience ofthe monitoring person who views the video by using a Mean Opinion Score(MOS) value. Allocating a bit rate to a camera may be rephrased assetting a bit rate to be applied when video data of a video captured bythe camera is transmitted to the monitoring apparatus 30.

FIG. 5 shows that a variation (inclination) in quality of experience islarge in a low bit rate region, while a variation (inclination) inquality of experience is small in a high bit rate region. That is, FIG.5 shows that the increase in bit rate and the increase in quality ofexperience are not proportional to each other. Furthermore, arelationship between the bit rate and the quality of experience is notlimited to the graph of FIG. 5 , and may be determined by another graphindicating a relationship in which the increase in bit rate and theincrease in quality of experience are not proportional to each other.

Returning to FIG. 3 , the encoding control unit 54 may change the valueof the quality q of experience by changing the bit rate to be allocatedto each camera as the encoding parameter, and may determine the bit rateto be allocated to each camera in such a way that the value of A1 inEquation (1) is maximized. The sum of the bit rates allocated to therespective cameras is in accordance with the constraint condition B ofEquation (2). Furthermore, the encoding control unit 54 may determine atleast one of the frame rate or the resolution to be applied to the videodata of the video captured by each camera according to the determinedbit rate. The encoding parameters controlled by the encoding controlunit 54 include the bit rate, and may further include the frame rate andthe resolution.

The encoding control unit 54 outputs the determined encoding parameterof the camera 61 to the encoding unit 57. Further, the encoding controlunit 54 outputs the determined encoding parameter of the camera 62 tothe encoding unit 58, outputs the determined encoding parameter of thecamera 63 to the encoding unit 59, and outputs the determined encodingparameter of the camera 64 to the encoding unit 60.

Each of the cameras 61 to 64 outputs the video data of the capturedvideo to each of the encoding units 57 to 60. The encoding unit 57outputs, to the communication unit 51, the video data to which the bitrate, the frame rate, and the resolution are applied as the encodingparameters acquired from the encoding control unit 54, for example.Similarly, the encoding units 58 to 60 output, the communication unit51, the video data to which the encoding parameters acquired from theencoding control unit 54 are applied. The communication unit 51transmits the video data acquired from the encoding units 57 to 60 tothe monitoring apparatus 30 via the network 40.

Next, a configuration example of the monitoring apparatus 30 will bedescribed with reference to FIG. 6 . The monitoring apparatus 30includes a reproducing unit 31 and a communication unit 32. Theconstituent component of the monitoring apparatus 30 such as thereproducing unit 31 or the communication unit 32 may be a softwarecomponent or a module whose processing is carried out by causing theprocessor to execute the program stored in the memory. Alternatively,the constituent component of the monitoring apparatus 30 may be ahardware component such as a circuit or a chip.

The communication unit 32 outputs the video data received from thetransmission apparatus 50 to the reproducing unit 31. The reproducingunit 31 reproduces the acquired video data, and displays the video on adisplay or the like that is built in the monitoring apparatus 30 or usedintegrally with the monitoring apparatus 30. The monitoring person viewsthe video displayed on the display. Furthermore, the reproducing unit 31transmits the information regarding the screen display to thetransmission apparatus 50 via the communication unit 32.

Next, a flow of communication control processing in the transmissionapparatus 50 according to the second example embodiment will bedescribed with reference to FIG. 7 . First, the communication qualityacquisition unit 52 acquires information regarding a quality of acommunication path between the transmission apparatus 50 and themonitoring apparatus 30 (S21). For example, the communication qualityacquisition unit 52 acquires information regarding a transmission timefrom when the transmission apparatus 50 transmits the video data to whenthe monitoring apparatus 30 receives the video data. Furthermore, thecommunication quality acquisition unit 52 calculates an availablebandwidth of the communication path after acquiring the informationregarding the transmission time as the information regarding the qualityof the communication path. The available bandwidth may be calculated by,for example, dividing the transmission time by the size of thetransmitted video data.

Next, the reproduction environment acquisition unit 53 acquires theinformation regarding the reproduction environment in the monitoringapparatus from the monitoring apparatus 30 via the communication unit 51(S22). For example, the reproduction environment acquisition unit 53 maybe the information regarding the screen display in the monitoringapparatus 30, the line of sight of the monitoring person, thereproduction delay, and the like.

Next, the priority level determination unit 55 determines the prioritylevels of the cameras 61 to 64 (S23). For example, the priority leveldetermination unit 55 may determine the priority level of the camera 61as 4, determine the priority level of the camera 62 as 3, determine thepriority level of the camera 63 as 2, and determine the priority levelof the camera 64 as 1 based on the traveling direction of the vehicle.Here, the larger the numerical value of the priority level is, the moreimportant the camera is. The important camera indicates that a videocaptured by the camera is more important than a video captured byanother camera.

Next, the quality-of-experience calculation unit 56 calculates thequality q of experience of the monitoring person when the monitoringperson views the video captured by each camera, by using the informationacquired from the encoding control unit 54 as a parameter. The encodingcontrol unit 54 outputs the information acquired from the communicationquality acquisition unit 52 and the reproduction environment acquisitionunit 53 to the quality-of-experience calculation unit 56. Furthermore,the encoding control unit 54 may output the bit rates and the framerates allocated to the cameras 61 to 64 and the resolutions and thecodec types of the videos captured by the cameras 61 to 64 to thequality-of-experience calculation unit 56. Furthermore, the encodingcontrol unit 54 may output installation locations of the cameras 61 to64, orientations of the cameras 61 to 64, camera types, a vehicle speed,operation information of the vehicle, and the like to thequality-of-experience calculation unit 56.

Next, the encoding control unit 54 determines the encoding parameter byusing the quality q of experience acquired from thequality-of-experience calculation unit 56 and the priority level pacquired from the priority level determination unit 55.

Next, a flow of encoding parameter determination processing according tothe second example embodiment will be described with reference to FIG. 8. In FIG. 8 , a flow of processing for determining a bandwidth to beallocated to each camera will be described. FIG. 8 shows detailedprocessing related to Steps S24 and S25 of FIG. 7 .

First, the encoding control unit 54 calculates a value of an objectivefunction in a case where bandwidths to be allocated to the cameras 61 to64 are increased by a predetermined amount (S31). For example, p₁ inEquation (1) is the priority level of the camera 61, and q₁ is thequality of experience for the camera 61. Further, p₂ is the prioritylevel of the camera 62, q₂ is the quality of experience for the camera62, p₃ is the priority level of the camera 63, q₃ is the quality ofexperience for the camera 63, p₄ is the priority level of the camera 64,and q₄ is the quality of experience for the camera 64.

For example, the encoding control unit 54 calculates the quality ofexperience for the camera 61 in a case where 100 kbps is allocated tothe camera 61, and calculates the value of the objective function byusing the calculated quality of experience and the priority level.Similarly, a value of an objective function in a case where 100 kbps isallocated to the camera 62, a value of an objective function in a casewhere 100 kbps is allocated to the camera 63, and a value of anobjective function in a case where 100 kbps is allocated to the camera64 are calculated. The priority level p_(i) is a value determined inStep S23 of FIG. 7 . The quality q_(i) of experience is uniquelydetermined, for example, in a case where the bandwidth (bit rate) isdetermined using the graph showing the relationship between the qualityof experience and the bandwidth shown in FIG. 5 . Even when the bitrates are the same, in a case where the quality of experience variesdepending on the frame rate, the resolution, and the like, the encodingcontrol unit 54 may adjust the frame rate, the resolution, and the likein such a way that the quality of experience is maximized at thecorresponding bit rate.

The encoding control unit 54 compares the values of the respectiveobjective functions, and determines a camera to which a bandwidth is tobe allocated (S32). For example, in a case where the objective functionin a case where 100 kbps is allocated to the camera 61 is larger thanthe objective function in a case where 100 kbps is allocated to anothercamera, the encoding control unit 54 determines to allocate 100 kbps tothe camera 61.

Next, the encoding control unit 54 determines whether or not a totalbandwidth of the respective cameras is smaller than the availablebandwidth (S33). As the available bandwidth, the value calculated by thecommunication quality acquisition unit 52 in Step S21 of FIG. 7 is used.Specifically, a case where it is determined in Step S32 to allocate 100kbps to the camera 61 will be described. In this case, 100 kbps isallocated to the camera 61, and no bandwidth is allocated to the othercameras, and thus, the total bandwidth of the respective cameras is 100kbps. In a case where the encoding control unit 54 determines that thetotal bandwidth of the respective cameras is smaller than the availablebandwidth, the processing of Step S31 and subsequent steps is repeated.Furthermore, in a case where a difference between the availablebandwidth and the total bandwidth of the respective cameras is less than100 kbps which is a predetermined increase amount, the encoding controlunit 54 may set the difference between the available bandwidth and thetotal bandwidth of the respective cameras as the predetermined increaseamount in Step S31 and subsequent steps.

Specifically, it is assumed that the encoding control unit 54 determinesto allocate 100 kps to the camera 61 in the first Step S32. In thiscase, in Step S31 repeatedly performed after Step S33, the encodingcontrol unit 54 calculates the quality of experience when 200 kbps isallocated to the camera 61 in a state where no bandwidth is allocated tothe cameras 62 to 64, and calculates the value of the objectivefunction. Further, the encoding control unit 54 calculates the value ofeach objective function when 100 kbps is allocated to each of thecameras 62 to 64 in a state where 100 kbps is allocated to the camera61.

In a case where it is determined in Step S32 that the total bandwidth ofthe respective cameras has reached the available bandwidth, the encodingcontrol unit 54 ends the encoding parameter determination processing.

As described above, the transmission apparatus 50 according to thesecond example embodiment can determine the bandwidth to be applied tothe video data of the videos captured by the plurality of cameras inconsideration of the priority level and the quality of experience. Thatis, by considering the quality of experience, the transmission apparatus50 can prevent excessive bandwidth allocation to video data of a videocaptured by a camera with a high priority level.

In addition, the encoding control unit 54 may use an objective functionA2 in Equation (3) defined as follows instead of the objective functionA1. The encoding control unit 54 may determine the encoding parameter insuch a way that A2 is maximized under the constraint condition B.

$\begin{matrix}\left\lbrack {{Equation}3} \right\rbrack &  \\{{A2} = {\max\frac{{\sum_{}^{}}_{i = 1}^{n}{p_{i}q_{i}}}{{\sum_{}}_{i = 1}^{n}r_{i}}}} & (3)\end{matrix}$

The objective function A2 is used to determine a bandwidth to beallocated to each camera in such a way that the value of the objectivefunction A1 per bit is maximized.

In addition, an upper limit of the bandwidth to be allocated to eachcamera may be determined as in Equation (4). q_(UB) represents an upperlimit value of the quality of experience.

[Equation 4]

q _(i) ≤q _(UB)  (4)

In a case where the bandwidth to be allocated is increased and thequality of experience reaches q_(UB), the allocation of the bandwidth tothe camera may be stopped.

In addition, the communication quality acquisition unit 52 may subtract,from the calculated available bandwidth, a bandwidth to be allocated tocommunication other than communication for transmitting the video dataof the videos captured by the cameras 61 to 64 to the monitoringapparatus 30. The communication other than the communication fortransmitting the video data may be, for example, communication fortransmitting sensor data detected by another sensor mounted on thetransmission apparatus 50. Alternatively, the communication other thanthe communication for transmitting the video data may be communicationrelated to an application used by a user in the vehicle.

The communication quality acquisition unit 52 may output, to theencoding control unit 54, a value obtained by subtracting the bandwidthto be allocated to the communication other than the communication fortransmitting the video data from the calculated available bandwidth. InStep S33 of FIG. 8 , the encoding control unit 54 may determine whetheror not the total bandwidth of the respective cameras exceeds the valueobtained by subtracting the bandwidth to be allocated to thecommunication other than the communication for transmitting the videodata from the available bandwidth.

As a result, the transmission apparatus 50 can transmit the video dataand other data according to the quality desired by the monitoring personof the monitoring apparatus 30 or the like.

Furthermore, the encoding parameter determination processing in FIG. 8may be used to determine a bandwidth to be allocated when data generatedin an apparatus other than a camera, such as a sensor, is transmitted,in addition to data generated in the camera. Further, in a case wherecommunication for transmitting video data has a higher priority levelthan that of communication for transmitting data detected in a sensor, abandwidth may be preferentially allocated to the camera, and then abandwidth may be allocated to the sensor.

Furthermore, the transmission apparatus 50 may periodically perform thecommunication control processing of FIG. 7 and the encoding parameterdetermination processing of FIG. 8 , or may perform the communicationcontrol processing and the encoding parameter determination processingwhen the available bandwidth greatly varies. The term “periodically” maymean, for example, a cycle of several hundred milliseconds to severalseconds (typically one second). As a result, the transmission apparatus50 can change the encoding parameter to be applied to the video data ofthe videos captured by the cameras 61 to 64 according to the change inradio quality or the like. Alternatively, the transmission apparatus 50may perform the communication control processing of FIG. 7 and theencoding parameter determination processing of FIG. 8 according to theoperation of the vehicle. For example, the transmission apparatus 50 mayperform the processings of FIGS. 7 and 8 at a timing when it isdetermined that the vehicle turns right or left. In a case where thevehicle is a self-driving vehicle, it may be found that the vehicleturns right or left from the operation of the self-driving vehicle or aplanned travel route, and in a case where the vehicle is a vehicle forwhich remote monitoring or driving assistance is performed, it may befound that the vehicle turns right or left at a timing when a blinker isturned on.

Third Example Embodiment

Next, a flow of encoding parameter determination processing according toa third example embodiment will be described with reference to FIG. 9 .In FIG. 9 , a flow of processing for determining a bandwidth to beallocated to each camera will be described. FIG. 9 shows detailedprocessing related to Steps S24 and S25 of FIG. 7 . In FIG. 9 , theencoding control unit 54 uses a priority order as the priorityinformation of the cameras 61 to 64. Here, it is assumed that the camera61 has the highest priority, the camera 62 has the second highestpriority, the camera 63 has the third highest priority, and the camera64 has the fourth highest priority. The priority order of each camera isdetermined by the priority level determination unit 55 in Step S23 ofFIG. 7 .

First, the encoding control unit 54 allocates a bandwidth b1 in such away that the quality of experience for the camera 61 becomes q (S41).Here, a graph indicating a relationship between a bandwidth b and thequality q of experience may be determined for each video of a camera.The graph showing the relationship between the bandwidth b and thequality q of experience may be similar to FIG. 5 . In this case, it isassumed that the bandwidth b1 allocated in such a way that the qualityof experience when viewing the video of the camera 61 becomes q followsa graph indicating a relationship between the bandwidth b and thequality q of experience for the camera 61. Next, the encoding controlunit 54 determines whether or not a value obtained by subtracting thebandwidth b1 from the available bandwidth calculated in Step S21 of FIG.7 exceeds a bandwidth b2 (S42). The bandwidth b2 is a bandwidthallocated in such a way that the quality of experience when viewing thevideo of the camera 62 becomes q.

In Step S42, in a case where the encoding control unit 54 determinesthat the value obtained by subtracting the bandwidth b1 from theavailable bandwidth exceeds the bandwidth b2, the bandwidth b2 isallocated in such a way that the quality of experience for the camera 62becomes q (S43).

Next, the encoding control unit 54 determines whether or not a valueobtained by subtracting the bandwidths b1 and b2 from the availablebandwidth calculated in Step S21 of FIG. 7 exceeds a bandwidth b3 (S44).The bandwidth b3 is a bandwidth to be allocated in a such way that thequality of experience when viewing the video of the camera 63 becomes q.

In Step S44, in a case where the encoding control unit 54 determinesthat the value obtained by subtracting the bandwidths b1 and b2 from theavailable bandwidth exceeds the bandwidth b3, the bandwidth b3 isallocated in such a way that the quality of experience for the camera 63becomes q (S45).

Next, the encoding control unit 54 determines whether or not a valueobtained by subtracting the bandwidths b1, b2, and b3 from the availablebandwidth calculated in Step S21 of FIG. 7 exceeds a bandwidth b4 (S46).The bandwidth b4 is a bandwidth allocated in such a way that the qualityof experience when viewing the video of the camera 64 becomes q. [0088]

In Step S46, in a case where the encoding control unit 54 determinesthat the value obtained by subtracting the bandwidths b1, b2, and b3from the available bandwidth exceeds the bandwidth b4, the bandwidth b4is allocated in such a way that the quality of experience for the camera64 becomes q (S47).

In Step S42, in a case where the encoding control unit 54 determinesthat the value obtained by subtracting the bandwidth b1 from theavailable bandwidth does not exceed the bandwidth b2, all bandwidthsthat can be allocated are allocated to the camera 62 (S48). The valueobtained by subtracting the bandwidth b1 from the available bandwidthdoes not exceed the bandwidth b2, which indicates that the valueobtained by subtracting the bandwidth b1 from the available bandwidth issmaller than the bandwidth b2.

In Step S44, in a case where the encoding control unit 54 determinesthat the value obtained by subtracting the bandwidths b1 and b2 from theavailable bandwidth does not exceed the bandwidth b3, all bandwidthsthat can be allocated are allocated to the camera 63 (S49).

In Step S46, in a case where the encoding control unit 54 determinesthat the value obtained by subtracting the bandwidths b1, b2, and b3from the available bandwidth does not exceed the bandwidth b4, allbandwidths that can be allocated are allocated to the camera 64 (S50).

Although a case where the cameras 61 to 64 have different priorities hasbeen described in FIG. 9 , but for example, the cameras 62 and 63 mayhave the same priority. In such a case, for example, in Step S42 of FIG.9 , the encoding control unit 54 may determine whether or not the valueobtained by subtracting the bandwidth b1 from the available bandwidthexceeds twice the bandwidth b2. In a case where the encoding controlunit 54 determines that the value obtained by subtracting the bandwidthb1 from the available bandwidth exceeds bandwidth b2×2, the bandwidth b2is allocated to the cameras 62 and 63 having the same priority. In acase where the encoding control unit 54 determines that the valueobtained by subtracting the bandwidth b1 from the available bandwidthdoes not exceed bandwidth b2×2, bandwidths corresponding to a half ofthe remaining bandwidths are allocated to the camera 62 and the camera63, respectively.

Alternatively, in Steps S42, S44, and S46, in a case where the encodingcontrol unit 54 determines that the remaining bandwidths do not exceedthe bandwidth b2, b3, or b4, the processing may be terminated withoutallocating the remaining bandwidths.

Although a case where the bandwidths are allocated to the cameras 61 to64 having different priorities in such a way as to obtain the samequality q of experience has been described in FIG. 9 , the bandwidthsmay be allocated in such a way as to obtain different qualities ofexperience depending on the priority order. For example, the encodingcontrol unit 54 may allocate a bandwidth in which the highest quality ofexperience is obtained to the camera 61 with the highest priority, andmay allocate a bandwidth in which the lowest quality of experience isobtained to the camera 64 with the lowest priority.

As described above, the transmission apparatus 50 according to the thirdexample embodiment can determine the bandwidth to be applied to thevideo data of the videos captured by the plurality of cameras inconsideration of the priority order and the quality of experience. Thatis, by considering the quality of experience, the transmission apparatus50 can prevent excessive bandwidth allocation to video data of a videocaptured by a camera with a high priority.

In addition, even in a case where a large number of bandwidths areallocated to a camera with a high priority to improve the quality ofexperience for the camera with a high priority, if the quality ofexperience regarding the videos of other cameras cannot be improved, thecomprehensive quality of experience for the videos of all the camerascannot be improved. Therefore, the transmission apparatus 50 cantransmit the video data to the monitoring apparatus 30 in such a way asto enhance the comprehensive quality of experience for the videos of theplurality of cameras by allocating the bandwidth in such a way as tosatisfy a predetermined quality of experience in descending order ofpriority.

Furthermore, it is possible to further improve the overall quality ofexperience for the videos of all the cameras by changing the quality ofexperience to be satisfied according to the priority order. For example,a video of a camera with a high priority can be said to be a video thatis gazed more by the monitoring person than videos of other cameras. Insuch a case, by assigning the bandwidth such that the quality ofexperience regarding the video of the camera with high priority ishigher than the quality of experience regarding videos of other cameras,it is possible to enhance the overall quality of experience as comparedwith a case of performing control in such a way that the qualities ofexperience for all the cameras are the same.

Furthermore, the encoding control unit 54 may allocate a minimumbandwidth to the cameras 61 to 64 before performing Step S41, and thenperform the processing of Step S41 and subsequent steps. As a result,the encoding control unit 54 can allocate a minimum bandwidth to eachcamera in order to transmit the video data to the monitoring apparatus30.

In addition, similarly to the second example embodiment, in thetransmission apparatus 50 according to the third example embodiment, thecommunication quality acquisition unit 52 may subtract, from thecalculated available bandwidth, a bandwidth to be allocated tocommunication other than communication for transmitting the video dataof the videos captured by the cameras 61 to 64 to the monitoringapparatus 30. For example, in Steps S42, S44, and S46 of FIG. 9 , theencoding control unit 54 may subtract, from the available bandwidth, thebandwidth b allocated to each camera and the bandwidth allocated tocommunication other than video data communication.

Furthermore, the transmission apparatus 50 may periodically perform theencoding parameter determination processing of FIG. 9 , or may performthe encoding parameter determination processing when the availablebandwidth greatly varies. As a result, the transmission apparatus 50 canchange the encoding parameter to be applied to the video data of thevideos captured by the cameras 61 to 64 according to the change in radioquality or the like.

FIG. 10 is a block diagram showing configuration examples of thetransmission apparatus 10, the monitoring apparatus 30, and thetransmission apparatus 50 (hereinafter, referred to as the transmissionapparatus 10 or the like). Referring to FIG. 10 , the transmissionapparatus 10 or the like includes a network interface 1201, a processor1202, and a memory 1203. The network interface 1201 is used tocommunicate with a network node (for example, eNB, MME, or P-GW). Thenetwork interface 1201 may include, for example, a network interfacecard (NIC) conforming to IEEE 802.3 series. Here, the eNB represents anevolved node B, the MME represents a mobility management entity, and theP-GW represents a packet data network gateway. IEEE represents Instituteof Electrical and Electronics Engineers.

The processor 1202 reads and executes software (computer program) fromthe memory 1203 to perform processing of a video transmission terminal10 or the like described with reference to the flowcharts in theabove-described example embodiments. The processor 1202 may be, forexample, a microprocessor, a micro processing unit (MPU), or a centralprocessing unit (CPU). The processor 1202 may include a plurality ofprocessors.

The memory 1203 is implemented by a combination of a volatile memory anda nonvolatile memory. The memory 1203 may include a storage disposedaway from the processor 1202. In this case, the processor 1202 mayaccess the memory 1203 through an input/output (I/O) interface (notshown).

In the example of FIG. 10 , the memory 1203 is used to store a softwaremodule group. The processor 1202 can perform the processing in thetransmission apparatus 10 or the like described in the above-describedexample embodiments by reading and executing these software modulegroups from the memory 1203. [0105]

As described with reference to FIG. 10 , each of the processors includedin the transmission apparatus 10 or the like in the above-describedexample embodiments executes one or more programs including a commandgroup for causing a computer to perform the algorithm described withreference to the drawings.

In the above example, the program can be stored using various types ofnon-transitory computer-readable media and supplied to a computer. Thenon-transitory computer-readable media include various types of tangiblestorage media. Examples of the non-transitory computer-readable mediuminclude a magnetic recording medium (for example, a flexible disk, amagnetic tape, or a hard disk drive), an optical magnetic recordingmedium (for example, a magneto-optical disk), a compact disc-read onlymemory (CD-ROM), a CD-R, a CD-R/W, and a semiconductor memory such as amask ROM, a programmable ROM (PROM), an erasable PROM (EPROM), a flashROM, or a random access memory (RAM). In addition, the program may besupplied to the computer by various types of transitorycomputer-readable media. Examples of the transitory computer-readablemedium include electric signals, optical signals, and electromagneticwaves. The transitory computer-readable medium can provide the programto the computer via a wired communication line such as electric wiresand optical fibers or a wireless communication line.

Note that the present disclosure is not limited to the above exampleembodiments, and can be appropriately changed without departing from thegist.

Although the invention of the present application has been describedabove with reference to the example embodiments, the invention of thepresent application is not limited to the above. Various modificationsthat can be understood by those skilled in the art can be made to theconfiguration and details of the invention of the present applicationwithin the scope of the invention.

Note that the present disclosure is not limited to the above exampleembodiments, and can be appropriately changed without departing from thegist.

Some or all of the above example embodiments may be described as thefollowing supplementary notes but are not limited to the following.

(Supplementary Note 1)

A communication control method in a transmission apparatus, thecommunication control method including:

estimating a quality of experience of a monitoring person who monitorsvideos displayed on a monitoring apparatus that has received video dataof the videos captured by a plurality of imaging apparatuses via anetwork, when viewing the videos; and

controlling communication for transmitting the video captured by each ofthe imaging apparatuses to the monitoring apparatus via the networkbased on the estimated quality of experience.

(Supplementary Note 2)

The communication control method according to Supplementary Note 1, inwhich

the imaging apparatus and the transmission apparatus are mounted on amobile body, and

the quality of experience is determined based on a state of the mobilebody.

(Supplementary Note 3)

The communication control method according to Supplementary Note 1 or 2,in which in the controlling of the communication, an encoding parameterof the video captured by each of the imaging apparatuses is controlled.

(Supplementary Note 4)

The communication control method according to Supplementary Note 3, inwhich the encoding parameter includes a bit rate of the video.

(Supplementary Note 5)

The communication control method according to any one of SupplementaryNotes 1 to 4, in which in the controlling of the communication, thecommunication is controlled based on priority information of each of theimaging apparatuses and the quality of experience.

(Supplementary Note 6)

The communication control method according to Supplementary Note 5, inwhich the priority information indicates a priority level, which is avalue allocated to each of the imaging apparatuses, or a priority orderof the imaging apparatuses.

(Supplementary Note 7)

A communication system including:

a transmission apparatus configured to transmit, via a network, videodata of videos captured by a plurality of imaging apparatuses; and

a monitoring apparatus configured to display the videos received via thenetwork,

in which the transmission apparatus

estimates a quality of experience of a monitoring person who monitorsthe videos when viewing the videos, and

controls communication for transmitting the video captured by each ofthe imaging apparatuses to the monitoring apparatus via the networkbased on the estimated quality of experience.

(Supplementary Note 8)

The communication system according to Supplementary Note 7, in which

the imaging apparatus and the transmission apparatus are mounted on amobile body, and

the quality of experience is determined based on a state of the mobilebody.

(Supplementary Note 9)

The communication system according to Supplementary Note 7 or 8, inwhich the transmission apparatus controls an encoding parameter of thevideo captured by each of the imaging apparatuses.

(Supplementary Note 10)

The communication system according to Supplementary Note 9, in which theencoding parameter includes a bit rate of the video.

(Supplementary Note 11)

The communication system according to any one of Supplementary Notes 7to 10, in which the transmission apparatus controls the communicationbased on priority information of each of the imaging apparatuses and thequality of experience.

(Supplementary Note 12)

The communication system according to Supplementary Note 11, in whichthe priority information indicates a priority level, which is a valueallocated to each of the imaging apparatuses, or a priority order of theimaging apparatuses.

(Supplementary Note 13)

A transmission apparatus including:

an estimation unit configured to estimate a quality of experience of amonitoring person who monitors videos displayed on a monitoringapparatus that has received video data of the videos captured by aplurality of imaging apparatuses via a network, when viewing the videos;and

a communication control unit configured to control communication fortransmitting the video captured by each of the imaging apparatuses tothe monitoring apparatus via the network based on the estimated qualityof experience.

(Supplementary Note 14)

The transmission apparatus according to Supplementary Note 13, in which

the imaging apparatus and the transmission apparatus are mounted on amobile body, and

the quality of experience is determined based on a state of the mobilebody.

(Supplementary Note 15)

The transmission apparatus according to Supplementary Note 13 or 14, inwhich the communication control unit controls an encoding parameter ofthe video captured by each of the imaging apparatuses.

(Supplementary Note 16)

The transmission apparatus according to Supplementary Note 15, in whichthe encoding parameter includes a bit rate of the video.

(Supplementary Note 17)

The transmission apparatus according to any one of Supplementary Notes13 to 16, in which the communication control unit controls thecommunication based on priority information of each of the imagingapparatuses and the quality of experience.

(Supplementary Note 18)

The transmission apparatus according to Supplementary Note 17, in whichthe priority information indicates a priority level, which is a valueallocated to each of the imaging apparatuses, or a priority order of theimaging apparatuses.

REFERENCE SIGNS LIST

-   -   10 TRANSMISSION APPARATUS    -   11 ESTIMATION UNIT    -   12 COMMUNICATION CONTROL UNIT    -   20 IMAGING APPARATUS    -   30 MONITORING APPARATUS    -   31 REPRODUCING UNIT    -   32 COMMUNICATION UNIT    -   40 NETWORK    -   50 TRANSMISSION APPARATUS    -   51 COMMUNICATION UNIT    -   52 COMMUNICATION QUALITY ACQUISITION UNIT    -   53 REPRODUCTION ENVIRONMENT ACQUISITION UNIT    -   54 ENCODING CONTROL UNIT    -   55 PRIORITY LEVEL DETERMINATION UNIT    -   56 QUALITY-OF-EXPERIENCE CALCULATION UNIT    -   57 ENCODING UNIT    -   58 ENCODING UNIT    -   59 ENCODING UNIT    -   60 ENCODING UNIT    -   61 CAMERA    -   62 CAMERA    -   63 CAMERA    -   64 CAMERA

What is claimed is:
 1. A communication control method in a transmissionapparatus, the communication control method comprising: estimating aquality of experience of a monitoring person who monitors videosdisplayed on a monitoring apparatus that has received video data of thevideos captured by a plurality of imaging apparatuses via a network,when viewing the videos, and controlling communication for transmittingthe video captured by each of the imaging apparatuses to the monitoringapparatus via the network based on the estimated quality of experience.2. The communication control method according to claim 1, wherein theimaging apparatus and the transmission apparatus are mounted on a mobilebody, and the quality of experience is determined based on a state ofthe mobile body.
 3. The communication control method according to claim1, wherein in the controlling of the communication, an encodingparameter of the video captured by each of the imaging apparatuses iscontrolled.
 4. The communication control method according to claim 3,wherein the encoding parameter includes a bit rate of the video.
 5. Thecommunication control method according to claim 1, wherein in thecontrolling of the communication, the communication is controlled basedon priority information of each of the imaging apparatuses and thequality of experience.
 6. The communication control method according toclaim 5, wherein the priority information indicates a priority level,which is a value allocated to each of the imaging apparatuses, or apriority order of the imaging apparatuses.
 7. A communication systemcomprising: a transmission apparatus configured to transmit, via anetwork, video data of videos captured by a plurality of imagingapparatuses; and a monitoring apparatus configured to display the videosreceived via the network, wherein the transmission apparatus isconfigured to estimates a quality of experience of a monitoring personwho monitors the videos when viewing the videos, and controlscommunication for transmitting the video captured by each of the imagingapparatuses to the monitoring apparatus via the network based on theestimated quality of experience.
 8. The communication system accordingto claim 7, wherein the imaging apparatus and the transmission apparatusare mounted on a mobile body, and the quality of experience isdetermined based on a state of the mobile body.
 9. The communicationsystem according to claim 7, wherein the transmission apparatus isconfigured to control an encoding parameter of the video captured byeach of the imaging apparatuses.
 10. The communication system accordingto claim 9, wherein the encoding parameter includes a bit rate of thevideo.
 11. The communication system according to claim 7, wherein thetransmission apparatus is configured to control the communication basedon priority information of each of the imaging apparatuses and thequality of experience.
 12. The communication system according to claim11, wherein the priority information indicates a priority level, whichis a value allocated to each of the imaging apparatuses, or a priorityorder of the imaging apparatuses.
 13. A transmission apparatuscomprising: at least one memory storing instructions, and at least oneprocessor configured to execute the instructions to; estimate a qualityof experience of a monitoring person who monitors videos displayed on amonitoring apparatus that has received video data of the videos capturedby a plurality of imaging apparatuses via a network, when viewing thevideos; and control communication for transmitting the video captured byeach of the imaging apparatuses to the monitoring apparatus via thenetwork based on the estimated quality of experience.
 14. Thetransmission apparatus according to claim 13, wherein the imagingapparatus and the transmission apparatus are mounted on a mobile body,and the quality of experience is determined based on a state of themobile body.
 15. The transmission apparatus according to claim 13,wherein the at least one processor is further configured to execute theinstructions to control an encoding parameter of the video captured byeach of the imaging apparatuses.
 16. The transmission apparatusaccording to claim 15, wherein the encoding parameter includes a bitrate of the video.
 17. The transmission apparatus according to claim 16,wherein the at least one processor is further configured to execute theinstructions to control the communication based on priority informationof each of the imaging apparatuses and the quality of experience. 18.The transmission apparatus according to claim 17, wherein the priorityinformation indicates a priority level, which is a value allocated toeach of the imaging apparatuses, or a priority order of the imagingapparatuses.